<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .main{
            /* display:flex  main,body,html{height:100%}
               定宽 + 自适应
            */
            display: grid;
            /* grid-template-columns 列的宽度 */
            grid-template-columns: 100px 1fr 2fr;
            /* /* grid-template-columns 列的高度 */ 
            grid-template-rows: repeat(3,300px);
        }
        .left{background-color: green;}
        .center{background-color: yellow;}
        .right{background-color: blue;}
    </style>
</head>
<body>
    <div class="main">
        <div class="left"></div>
        <div class="center"></div>
        <div class="right"></div>
    </div>
</body>
</html>